Telephone receiver



1,628 May 10, 1927. I A. P- YOUNG I ,383

TELEPHONE RECEIVER Filed April 14, 1925 Fig. I.

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'TELEPEQNE RECEIVER,

.lpplication filed April M, 1925, Serial No.

present invention relates to electromagnetic circuit comprising a permanent magnet, attached to the ends of which are d particularly to telephone receivers or transmitters for use in connection with wireless or ordinary telephony or telegraphy. Devices of this type have been d sclosed in my copen drug application, Serial No. (i40,060, filed May-1.9, race, of which this application is a continuation in part.

The invention consists in so forming each pole piece that at its junction with the per-.

:zmanent magnet it embraces the end of themagnet and makes a close tit therewith.

Each pole piece may be formed from, a soft iron strip and bent to pressed on to the end Alternatively two pole pieces with press.

a connecting strip of out of a plate or ordinary shape and finally of the magnet in a metal may be stamped dynamo iron, a

number of the stampings riveted together, the magnet fitted into'p lace and then the connecting strip machined aw ay. The

assembly of pole pieces and magnet made by eit ier of the above mounted in a casing methods may then be or moulded nto a composite insulatingmaterial, such for instance I as synthetic resin, which also forms the body and easing of the instrument.

The novel features which I believe to be characteristic of my ,with particularity in the appended claims.

My invention itself,

best be understood invention are set forth however, both as to its organization and method of operation will by reference tothe followingdescription taken in connection with the accompanying drawing in which Fig. 1

shows a side view pieces and magnet;

of the assembled pole Fig.2 is a side view of a modification; and Fig. 3 is a cross sec tiona'l view of a telephone receiver embodying my invention, certain, parts of the re ceiver ness.

being omitted in the interest of clearthe magnetic circuit includes an approximately L- shaped pole piece,

having one limb bent round substantially through 180 away from i the other arm 15; or the end of one limb limb; The resulting shape is like a U 13 having unequal parallel arms 14 and g l5, and the f stantially ri 12 projecting at subthe end of the joined to the horizontal 22,97 and m GIGal; min a es, it, was, i

limb of a letter l... The permanent magnet 16 may be a flat bar as here shown or of curved pattern, and it is arranged with its polar extremities proje ting into the U shaped hollows 17 of each pole piece,

According to one method of carrying out the invention as illustrated in Fig. l, a fiat strip of soft iron is bent into the shape previously described. A small slot, not shciwn, may be provided at the base of the U-shaped portion 13 to facilitate bending, and the arm 15 of the Li -shaped portion may be curved at its extremity away from the other arm '14; as shown at 18, in order that the base of the limb 12 may be raised substantially clear'ofthe surface of the magnet 16 so as to 'utilize as much as possible of the length of the magnet and to provide a suitable seating for the coiL- In the preferred construction, a short flat bar magnet of cobalt steel is placed with its ends projecting into the hollows of the ill-shaped portions 13,

the width of the magnet being substantially equal to the width of the po e pieces at each end. The ends of the magnet are preferably made rough or provided with recesses so that the soft iron of the pole pieces will adhere firmly thereto. 'llhe parts are then placed in a gig and pressed firmly together. The Whole'may then be placed together with a composlte insulating material in the interior of. a mould and the composite insulatmg material may be moulded to secure the nagnetm structure into position in a casing or itself moulded to form the body and casingof the instrument.

'According to another method of carrying the invention into 'efiect as applied to a watch type telephone receiver, as is illustrated in'l igsl 2 and 3, stampings of a thick- Iiess say, of .04 inch, are made of the shape above describedbut with an integral connecting strip of metal 19 joining the ends of the pole pieces where 'm contact with the magnet. When the magnet isin place this connecting strip is pre from the meet, i. e. by the revision. of arecess 20, so that it can be easi y machined away subsequently without damaging the magnet. These stampings are riveted toether in ancient number to form a suitable width or pole piece and the permanent magnet'is then pressed into. place, the stampin s being of such dimensions that at the en s otthe met a tight he is secured,

till

it 'erably spaced away ill) described, in the drawing; the composite lnsnlnting materiel issliown inonlcletl into the casing This method of "forming" the pole pieces lies the sdvnntage that the correct splicing; of the coil limbs 12 from one 1 d from tlieinngnet is secured zinotlier nntonniti k The n net in either cnse inn be megnctizerl either before or litter assembly.

'll hnt ll claim as new nnd desire to secure by Letters Potent of the United Stet-as, is: 1. .rl tel lone receiver or l" e device conr prising; n at ber permanent, magnet end it pole a, embracing one end of snicl magnet end in contnct with the end surface thereof.

9. ebbone receiver or like device cornprisi' Y ber permanent magnet pole piece ellllfililfilllg each end oi said magnet,

snid le piece comprising two portions ed- 'jIlCfl-llllib snbstsntinlly pernllel to one entliird portion perpendicular to 1. portions and edn ctecl to support; n, trending.

sees

closely embracing one end of said magnet and having a portion substantially parallel to but spaced from said magnet, end at second portion substantially perpendicular to said parallel portion and adapted tosupport a. Winding.

5. A telephone receiver or like device C0111- prising it list bnr iierrnnnent magnet, a bent pole piece embrncing one end of said inegnet and in contact with the end surface thereof, snid pole piece baving a portion spaced from but substantially parallel to said magnet, said magnet end a portion of said pole piece being einliicddeil in insulz1ting material.

lln "Witness ivliereoit, have hereunto set my band this 20th day of lvlsrch, i925.

Alttl'lllllift PlllllvlltUdE YUUNG. 

